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Suggestions for power take-off for screenwash pump


Colin Lindsay

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I'm going to fit an electric screenwash pump to the 13/60 since the bellows pump has failed; easiest thing is to route a power cable from the battery but it's not the tidiest. 

I'm curious to know if anyone has taken a power source from anywhere else behind the dash, closer to the area of the existing screenwash bottle to keep cables to a minimum? I'll have a small auxiliary switch under the dash, but with no fuse box I'm planning first before cutting or splicing into a circuit - probably green - and regretting it later.

All hints and tips very welcome.

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Thanks Pete and Rob; the idea came to me as I reconnected the wiper switch - can't I just piggy back from that? Then again, having melted two 1200 looms due to the wiper circuit in the past, I thought I'd check I wasn't going to melt anything further.

Thanks, too, PMV - that's an excellent setup, but I'm just fitting a simple sprung switch to the dashboard lower support; sprung rather than switched so that it works whilst depressed but stops when released.

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2 hours ago, Colin Lindsay said:

Thanks Pete and Rob; the idea came to me as I reconnected the wiper switch - can't I just piggy back from that?

Yes, my only hesitation about that is I think the wiper switch is a ground-side switch and the green power wire goes from the brake pedal to the wiper motor. However, no reason you can't piggy-back from the motor to the pump and switch the ground-side of the pump too.

Edit: Of course I'm thinking Mk1 Vitesse or Mk3 Spitfire, neither of which use the combined switch and pump thing. The car I have with one of those is a Mk3 GT6, which has 2-speed wipers and a supply-side-switched wiper motor. So now I can't remember what the 13/60 wiring is actually like.

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The 13/60 has the two wires to the switch, and the switch just earths the power. The screen wash is a bellows / pump design in the same switch, which no longer seems to be pumping. 

It seems simple to piggy-back off the powered terminal to the switch, and earth via a 12v motor through a small flick switch. There's nothing else in that area to take power from bar the gauges.

I just wanted to confirm that this won't melt the existing switch wiring, by seeming straightforwardly simple, but upsetting something else along the line... :(

DSCF2051.jpg.65c27f328b8717f37ce283f372e1b2c1.jpg

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the bellows is just that  , its empty space   the valves that make it work as a pump are one in the bottle and either one in the tee split to the jets or in the jets base 

if the bellows does diddly squat then the simple valves are failed  

many little used SW seem to develope a gloopy mix with slows the valves , i only use SW addative  no wash up stuff and the electric on the 2000  needs a wipe and blow 

to make it work  if left for a week or so , maybe it needs more agitation

Pete 

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My 13/60 had a non return valve in the bottle, it was an inline type (aquarium). when the system was left for any length of time it would 'seize' and not squirt. With a lot of effort it could be persuaded to work again. It could be that your symptoms of the bellows not working is just the valve sticking.

A few weeks ago I replaced it with one designed to go into the washer bottle of a mini, old type of mini.

When I tested it by sucking through it the effort needed was far less than the inline one.

clapet-anti-retour-liquide-lave-glace-immerge-austin-mini.thumb.jpg.79d98ee18726769c6d119a5124b6be65.jpg

Time will tell if this suffers the same problem.I bought it from a company in France, their reference for it is 12434, no idea if this is just their stock number of an official part number.

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2 hours ago, Colin Lindsay said:

The 13/60 has the two wires to the switch, and the switch just earths the power. ...

It seems simple to piggy-back off the powered terminal to the switch, and earth via a 12v motor through a small flick switch.

If the switch has two wires and earths something (i.e. one of the wires goes to earth) then it's a ground-side switch and there is no "powered terminal". The power feed is directly to the wiper motor. This is the standard wiring for the square, single-speed wiper motor.

Where are you fitting the pump? I put mine on the engine side of the bulkhead (much easier access there) so the obvious wiring is to take a green wire from the green terminal of the wiper motor to the pump +ve, then a (green/black?) wire from the pump -ve to the switch, then the switch to ground.

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Apologies for the non-official terminology, if electricity comes through a switch which simply completes a circuit then, to me, one side is powered - power comes in - and one goes to earth - the 'ground side'. In the wiper circuit it's permanently live until earthed so if I test the 'in' side of the wiper switch I'll get a positive result. It's no matter if the current comes directly from the battery or via the wiper motor, it's the same end result - you know what I'm getting at!

What I had hoped to do was to use the 'in' cable at the switch to provide power to the washer pump switch which is six inches away, then from the switch to the pump, through the pump and back to earth at the wiper motor earth point (pump will be on the bulkhead closeby). 

Reference the bellows from the posts above; it pumps when placed in water, but through both sides. I've tried replacement one-way valves and when I do that, there's no water flow at all. This was with the switch removed in my kitchen, and all sorts of permutations and swapovers, but no pumping at all. If I prime two pipes, one to each spigot, and hold my finger over one, the other pumps, but then there's no water getting in. I'm assuming the pump is uniflow - no internal valves, just a rubber bellows - and a one-way valve on either intake will direct the flow out of the other. I've tried three different valves - if I blow, they seal, if I suck, they allow air in, but yet pumping the push-lever does not result in movement of water. I'll experiment a bit more if I can get to a local aquarium shop over the weekend...

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Colin - It appears that I picked up the power on mine from the wiper switch live, as Pete suggests. There is a connector doubler on the back of the wiper switch with one of the leads going to the washer switch. Looks like it may have been simpler than taking a lead from the fuse box. Hope this helps.

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21 minutes ago, Badwolf said:

Colin - It appears that I picked up the power on mine from the wiper switch live, as Pete suggests. There is a connector doubler on the back of the wiper switch 

I think that's what actually gave me the idea in the first place, but was waiting for the sharp intake of breath and the 'you don't want to do that!' reply... cos if you do that, then every time you press the washer switch... the wipers will come on...

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2 hours ago, Colin Lindsay said:

Apologies for the non-official terminology, if electricity comes through a switch which simply completes a circuit then, to me, one side is powered - power comes in - and one goes to earth - the 'ground side'. In the wiper circuit it's permanently live until earthed so if I test the 'in' side of the wiper switch I'll get a positive result. It's no matter if the current comes directly from the battery or via the wiper motor, it's the same end result - you know what I'm getting at!

What I had hoped to do was to use the 'in' cable at the switch to provide power to the washer pump switch which is six inches away, then from the switch to the pump, through the pump and back to earth at the wiper motor earth point (pump will be on the bulkhead closeby).

Unfortunately, no. That's all wrong.

If you have a ground-side switch and you look at it with a multimeter while turned off, you will see the "top" side showing battery volts. You assume that's "power". It's not. It's the bottom side of the wiper motor - the middle of the circuit. The moment you turn the wipes on, that point goes to ground, because the switch takes it there. If you power your pump from that point, as you describe, it will probably work when you test it. But it will not work with the wipers on.

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51 minutes ago, NonMember said:

Unfortunately, no. That's all wrong.

If you have a ground-side switch and you look at it with a multimeter while turned off, you will see the "top" side showing battery volts. You assume that's "power". It's not. It's the bottom side of the wiper motor - the middle of the circuit. The moment you turn the wipes on, that point goes to ground, because the switch takes it there. If you power your pump from that point, as you describe, it will probably work when you test it. But it will not work with the wipers on.

That's why I asked you all in the first place. The wiper circuit has me totally confused, as is plain to see. I had assumed that if I turn on a switch that earths the circuit, then it's got to have current coming to it to earth; therefore it's a good place to take a spur from for another component. Stringing a long cable from the battery is becoming more appealing by the minute.. :)

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Like Pimp my Vit has done, I connected the electric pump to the spare 'accessory' terminal  on the ignition switch and fitted an inline fuse of suitable rating. I've used a trad lucas toggIe switch for the  pump mounted on a small bracket under the dash. I decided to mount the pump inside the bulkhead rather than engine side. Its then more convenient to divert the pipework from the old pump. Although I'm not obsessed with originality, it keeps the bulkhead looking tidier, at the small expense of hearing the pump motor more readily! The original pump wiper switch still works ok. 

 

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15 hours ago, Mathew said:

I would seriously consider putting in a fuse box! I've had a fire in a car due to an earth fault. Not fun. Luckily driving it at the time and could turn the ign off to stop the current. Close run thing, wrapped in insulation tape got me home! The wires not me!!!!

I had a loom fire start as I was off to fuel up for Spa 2 years ago. Never did find the actual cause. After that, I bought a VW fusebox, and put a main link fuse (100A) to feed my normal (8 way) fusebox, and fused the alternator to 60A, having had a Lucas Re-con, emphasis on the con, alternator internally short with wife and 2 small kids in our herald. That was worrying, and why I won't use ACR alternators as they have all been reconditioned by now, or are built with the same rubbish parts. 

Fuses are your friend!

 

EDIT the best bit about the spit loom fire was I pulled over, and quickly got the battery disconnected so only the loom melted. When I called breakdown, teh lady asked me if my hazards were on. me "No". her "but you must!". me "but the battery is disconnected" her "then re connect it" me "but the car will catch fire and burn if I do" her "err...... why" me "because the reason I broke down is teh wiring loom has burnt, disconnecting the battery has stopped further damage"  She didn't mention it again... but a nice chap from the AA appeared soon after, towed me home and we had a chat about his Mini etc. And I took my Toledo to Spa.

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I've had three loom fires.

The Herald, on its last journey before being scrapped, shorted out some wiring behind the dash. Lots of smoke then it burned out and that was it.

The GT6, many years ago, had a power wire for a radio that hadn't been fitted since before my brother owned it. The fuse holder came undone, the live end dropped and the metal bit touched the floor. Lots of smoke from between my legs! I quickly pulled over, removed the offending wire from the ignition switch, and continued my journey. Fuses may be your friend but inline fuse holders sometimes aren't.

And then there was the Dolomite. An 1850 that had been re-shelled in a 1500HL body, and not terribly well. The main power distribution - connecting the battery, alternator, and then the pre-fuse stuff - on a 1500 is an H-shaped piece of copper in a thermoplastic housing (with four big Lucar connectors plugged into it). This is mounted on the LH inner wing. Since my car was an 1850, that location is directly above the exhaust manifold. The fixing lug broke. I'd driven down to church and parked. I came out an hour later and found the car had no battery power. On opening the bonnet I saw that said terminal block had fallen off the wing, landed on the hot exhaust manifold, melted, then shorted the battery via the heavy gauge main supply wire and the engine earth strap. The loom had caught fire, burned until the main supply wire broke, at which point there wasn't enough heat being put in to sustain a fire in the electrical insulation material so it went out. I managed to repair the car with a single 2ft length of 40A brown wire. I also re-made the housing for the power terminal block in a less vulnerable material.

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